Improving the efficiency of a rectification circuit is an important measure of increasing circuit performance. In a power conversion circuit, due to the increase of power, the importance of conversion efficiency is continuously increased. Input signals and loadings of circuits are generally mixed up of linear and nonlinear characteristics. The conventional ways can only conduct on a switching element that is connected in parallel with a rectifier diode according to the phase of an input voltage to handle a sinusoidal wave input signal used in combination with a resistive linear loading. However, when the loading in not linear or the input signal is a direct current, the switching element that is connected with a rectifier diode would lose functionality of simply fail.
Further, the power consumption of a rectifier diode in a rectification circuit is increased with the increase of an electrical current flowing therethrough. To reduce the loss caused by the diode, a switching element, such as a metal-oxide-semiconductor field-effect transistor (MOSFET) is connected, in parallel, to two ends thereof, and the MOSFET is set on when the diode is conducted forward in order to reduce power consumption of the diode. However, the conventional rectification circuit determines if to conduct on/off the switching element according to the result of detection of the phase of an input voltage. When the loading circuit comprises a capacitive element or other non-resistive loading circuit, which makes the input current a nonlinear signal, the loading circuit would generate a reversal current, leading to a shorting issue and making the rectification circuit fail. Or, when the input is an alternate current that has an extremely long period or a direct current, a floating connection bootstrap power supply would lose the performance of supplying power, leading to failure of the control circuit.